This invention relates to a rotary fluid flow switch and more specifically to a rotary air valve of a musical instrument.
Rotary valves are highly regarded for use in musical instruments due to their quick action and relative simplicity of structure as compared to piston type valves. Prior rotary valves suffer, however, from the disadvantage that they add overtones to the sound of the instrument when played. These overtones are the result of sharp bends in the air passage which occur either inside the valve rotor or at the junction of the valve rotor with the instrument tubing. Whenever the sound waves traveling through an instrument's sound passage are required to make a sharp turn, a certain portion of the waves reflects off the inside walls of the passage. Such a partial reflection reduces the energy of the fundamental wave and produces an undesirable overtone.